Farafenni Health and Demographic Surveillance System

For many populations in the less developed countries, delivery of effective health care is usually a challenge. This is mainly due to lack of the requisite information to guide decision making processes as to how the meagre resources available may be utilised to serve the majority of the population. These include the prevalent illnesses affecting the population; the proportions dying from specific diseases; and the rates at which death occur among:
• children under five years;
• women whilst pregnant, at delivery and within six weeks after delivery;
• adolescents; and
• adults aged 20 to 60 years.
Without such information, the healthcare system cannot be properly evaluated to draw up effective strategies for reducing the burden of disease in the population, and therefore reduce the death rates among the different age groups of the population.
The Farafenni HDSS follows up a community of about 55,000 people in rural Gambia, regularly updating the status of every individual in terms of their residency, health status, and demographic events that affect them. These range from pregnancy observation to the outcome; and from birth or in-migration to death or out-migration. The information generated enables thorough assessment of the health problems of the population with recommendations of specific strategies to adopt to enhance efficient healthcare delivery.

Like most other countries in Sub-Saharan Africa, The Gambia is characterised by incomplete vital registration system, and the health system does not routinely generate key information required to guide health care delivery planning, implementation and evaluation. The majority of deaths occur at home and therefore are usually not registered and their causes unascertained. The general unavailability of cause-of-death information therefore limits efforts to establish a solid evidence base for health policy formulation. It also presents significant challenges for effective planning, monitoring and evaluation of health care delivery systems. It is against this background that the Farafenni Health and Demographic Surveillance System was instituted and operated since October 1981, and supported several epidemiological investigations and clinical and drug trials. It also served as the platform to monitor and confirm that this sub-national population in The Gambia achieved its MDG4 target seven years before the target date of 2015.

However, recent analyses and publications on causes of death between 1998 and 2007 revealed relatively high pregnancy and non-communicable disease (NCD) related mortality. The system will therefore be further enhanced in the short term through the following strategies:

• Collecting antenatal and all relevant maternity-related information to facilitate investigations into the risk factors sustaining the high level of maternal mortality in rural Gambia, and propose strategies of enhancing safe motherhood;
• Providing a platform for the design and evaluation of strategies for instituting NCD surveillance in rural Gambia to establish the prevalence of common NCDs (such as diabetes, hypertension, etc) and understand the risk factors responsible for the rise of these diseases in rural Sub-Saharan African populations;
• Extend the collection of detailed age-specific health and demographic information from children to adolescents so as to ascertain the prevalent health problems of rural Gambian adolescents, especially in relation to reproductive health, as well as access to and utilisation of health care services.
Fieldwork is organized into a series of 4-month periods of demographic updates. A team of fieldworkers are assigned specific sets of villages for the periodic updates, and ensure that each compound is visited at least once within the period, and every household interviewed. Using a list of all residents of each household called the Household Register, the fieldworkers verify and update the recorded information for all households with the Household Head or reliable adult household member. All deaths, births, in and out migrations, pregnancies, and marriages are recorded during each visit. Pregnancies are followed for outcomes of miscarriage, still or live birth, giving more complete coverage of neonatal deaths. Verbal Autopsies are conducted as much as possible for each death using the WHO 2012 standard VA questionnaires, and coded using InterVA4 to establish the probable cause(s) of death.